Grinding machine



May 28, 1940. H. E. KITCHEN GRINDING MACHINE 2 Sheets-Sheet 1 INVENTOR Harry E. Knchen BY f ATToRN Y Filed March 31, 1959 May 28, 1940.

H. E. KITCHEN GRINDING MACHINE I Filed Mar 'ch 31, 1939 2 Sheets-Sheet 2 I INVENTOR Harry E Ai/c/zen W f g; ATTORNE p. ...c zs. o, v 2,202,581

UNITED TAT PATENT O GRINDING MACHINE Harry E. Kitchen, Buffalo, N. ..Y., assignorto Farrel-Birmingham Company, Inc., Buffalo,

.1. Application ara. 31,1939, Serial No. 265,194 3 Claims. (Cl. 51-96) This invention relates to a machine for grind that it is concave relative to the plane of the ing the cutting edges of cutters which are used in cutter ,face. The dot and dash line I5 (Fig. 5) the shaping-generating.process of forming gears.. indicates a projection of the plane of the edge The machine is'particularly devised to perform Ila, and it affords comparison with the relatively 5 the grinding operations'demanded in the pro-. curved edge Illa. After the facet l2 and groove duction of the type of cutters disclosed in, coll are ground, a third and final grinding operapending application Serial No. 248,460, filed .Detion forms a facet which defines a tip cutting cember 30, 1938. In said. copending application, edge llj e an improved form of. double helical or Sykes type The machineincludes a grinding unit and an gear is disclosed, together with the cutters for underlying cutter jig) unit, and it will be under- 10 producing the same, which cutters include cut-r. stood that, with slight modification, many of the tingv edges of modified involuteform: The presadjustable grinding machines known in the art ent invention provides an accurateand practical may be substituted for the grinding unit herein method of grinding such edges, either in the disclosed. 'Both units are supported on a fixed original production of anew. cutters or in repedestallfl having a hub 2| which contains aver- 15 sharpening dull'cutters, as is more fully, set forth tical bearing 22." An integral horizontal sli e". in the accompanying specification and, drawings, isformed on the rear of. the pedesta nd it whereinz" serves as a supportfor a grinder standard 2| Fig. 1 is a side elevationof' the grinding mawhi h s f m d w t a pl tary ib p r chine; g tion 25. The standard 24 carries a radially ad- 20 Fig. 2 is a top view thereof; justable post 26 having a horizontal bearing 21,

Fig, 3 is a fragmentary end view showing parwhich bearing in turn carries a lotatably and ticularlythe cam action of the cutter supporting x lly a j table grin ing head 28. The extable; 1 H tremity of the head 28 incorporates a suitable Fig. 4-is an enlarged sectionthrough the grindtransverse b n Structure i ec v ng a. 25

mg wheel and cutter tooth, taken on the line 4-4 r ndi wh l shaft 9, p xt mity of of Fig. 1'; r r 1 i which a grinding wheel is fastened. The op- 'Flg.--5 is an enlarged fragmentary perspective posite extremity of the shaft 29 carries a pulley view of a completelyground cutter tooth; 3|, which is connected to a suitable source of 30 Fig. 6 is a section taken on the curved line 6.6 power (not Shown) by a elt 32. It will be ap- 30 of Fig; 5, showingdiagrammatically several posipa t With h a 0f the s ve al jus tions of the grinding wheelduring the hollow merits. the [grinding he 30 ybe fi ed in grinding Drocess;- 1 a any desiredangularor spacial position vrelative Fig. '7 is a perspective view of 'a cutter tooth B01111? bearing 22 for Operating on an underlying whose obtuse edgeis ground through awrelative mitten 35 lineal movement of the grinding "wheel; and. 1 F 8 1 t0 3, the Cutter s mou ted for arcu- Fig.8 is a diagrammatic side elevation of a i movement beneath the g din wheel by a machine-for producing. cutter of Hg 'L oscillatablehead which includes a *A typical cutter C of the helical type menh vi a depending shaft rotatably carried in th tioned'is bestillustrated in'Figs..4to 6, where it bearing t its ea argin, the table 34 is 40 will be observed that the cuttingface F of each mB w h pa d p n in 88 35, in each tooth includes tapered obtuse and acute flanks -Wh ch a pr ject ng p fl is fastened .A "and H- respectively (Fig. 4), resulting from handle 31 is secured to one side of the table to the original helical formation of the teeth plus a facilitate manualv oscillation thereof. The rear slight clearance angle. As is well known in the extremity a plate 38 s eceived between the art, the acute flank II is ground to a cutting lugs 35, and the plate 38 is formed with bearings angle of somewhat less than 90 degrees by grind- 39 or receiving the pintles ThuS, the plate ing asuitable facet l2 in the tooth face. The although constrained to be rotated with the cutting edge Ila thus provided lies accurately in table 34, may, when desired, be given an addi- 5 a plane normal to the face of the cutter. tional vertical hinging movement about the pin- The grinding of the obtuse flank I0 is the pari ties 36. ticular concern of the present machine, and as A bracket 40 is fastened beneath the projecting will be observed in Fig. v5, the cutting edge vIla end of the plate 38, and it is formed with slotted thereof is defined by a'face groove H of toric depending legs 4|. A bolt 42 having washers 43 shape. This edge differs from'the edge Ha in and a spacing bushing 44 thereon, is entered in 5 the pitch the slotted legs and clamped thereto by lock nuts 45. A sleeve 46 is rotatably carried on the bushing 44, and such sleeve 46 serves as a hub for a cam roller 41. The roller 41 may be secured in various axial positions on the sleeve 46 by a lock screw 48.

A radially formed angle member 50 is secured to the front of the pedestal hub 2|, and itshorizontal leg 5! is disposed immediately under the roller 41. A cam 52 (Fig. 3), having a raised surface 53, is disposed on the upper face of the leg 5|, and it may be fixed in any radial position thereon by a clamp 54. The cam 52 is fash-. ioned so that it actually is a small sector of a cone whose center is the axis of rotation of the table. Thus, the describedaxial adjustment of the cam roller 41 permits the'selective positioning thereof on higher or lower lift portions of the cam 52.

and it is formed with a shank 56 uponwhich a cutter C is rotatably positioned. The cutter is releasably held in a fixed rotative position under the grinding ing of a flexible finger 51 secured in a bracket 58 on the plate 38. The finger 51 engages the acute edge of one tooth and the flank of an adjacent tooth, and thus firmly positions the cutter against rotation during each grinding operation; Upon completion of each grinding operation, the cutter is rotated one tooth space, during which the finger is flexed sufficiently to enter the adjacent tooth l It will be observed'in Fig; 2 that the tooth being ground is spaced from the vertical center of rotation of the plate 38, and thus as the plate and table assembly are oscillated, a radial groove is ground in the face of the tooth (Fig. 4) which groove is modified to match substantially the contour of the tooth by .adjusting the plate 38 to the proper normal angle by raising-or lowering the supporting cam roller 41. To obtain the additional hollow grinding feature previously mentioned, the cam 52 is located so that the passage of the roller 41 over the high point on the cam face 53 is coincident with the passage of zone of the tooth under the grinding wheel. Thus, as the cutter head is manually oscillated through the short grinding arc, the plate 38 rises and falls under guidance of the cam 52. 'As best illustrated in Fig. 6, it will be seen that the bottom B of the groove is. accordingly curved relative to the theoretical horizontal plane, as indicated by the dotted line 60. Other portions of the groove, including the cutting edge Illa, are likewise of concave character.

The machine may be easily adjusted to grind the facets l2 and 16, in which case the hollow grinding feature is not necessary, and the cam 52 may be removed and replaced by a flat member.

wheel by an indexing device consistcated characteristics. this type, a machine such as ically in Fig. 8 may be used. This machine is basically similar to that of Fig. 1, with the exception that the cutter head BI is formed with a carriage 62 which is mounted in slides to provide for lineal movement thereof. The carriage has a pivoted cutter plate 53 attached to it, and such plate is raised and lowered, as in the first embodiment, by a cam and rolierarrangement 64. The grinding wheel 65 is similarly fixed for rotation in the desired angular position.

It will be understood by art that the grinding procedure herein provides an advantageous relation between the grinding wheel and work, which permits repeated resharpening by the same apparatus without complications of any nature. Additionally, the machine is 'sufliciently flexible in adjustment of grinding-wheel and cutter head to encompass in its range the grinding of cutters of 'all the commonly used pressure and helix angles.

It is-not intended that the invention be limited to the precise forms of mechanical elements disclosed, as it will be obvious that the desired relative movement of the grinding wheel and work may be produced in other manners with-.

out departing from the inventive concept I claim: H. 1. A grinding machine having in combination a grinding wheel, said head for oscillating movement beneath said.

wheel, a cutter supporting plate carried for I the head on an axis transhinged movement by verse to the axis of oscillation of the head, ,a

cam roller carried by the plate, cam means en-- gaged by the roller during movement of the head for gradually raising and lowering the plate during movement ofthe head in each direction, and adjusting means organized with said cam means for varyingthe normal angle of the hinged plate relative to the axis of oscillation of the head- 2. A grinding machine having in combination a grinding wheel, a head, means for mounting said head for oscillating movement beneath said wheel, a cutter supporting plate carried for hinged In producing a groove of; shown diagrammat-ag those skilled in the described, I

30 a head,means for mounting movement by the head on an axis transverse to the axis of oscillation of the head, a cam roller carried by the plate, a stationary cam supporting the roller andplate and formed to cause the uniform raising and lowering of the hinged plate during movement of the head in each direction.

3. A grindingmachine having in combination a grinding wheel, a head, means for mounting.

said head for oscillatingv movement beneath said wheel, a cutter supporting plate carried for hinged movement ,by the head on an axis transverse to the axis of oscillation of the head, a cam roller carried by the plate and mounted on a radialaxis relative to the axis' of oscillation of.- saidhead,

means for adjusting the roller axially, and a fixedv cam upon which saidroller rides, said cam hav- 1 ing a radially variable rise.

HARRY E.- KITCHEN. 

